Troubleshooting Procedures; 1 ] Control Panel Related; 2 ] Telephone Related - Brother FAX4759 Service Manual

2.4

Troubleshooting Procedures

[ 1 ] Control panel related

Trouble
(1) LCD shows nothing.
(2) Control panel inoperative.

[ 2 ] Telephone related

Trouble
(1) No phone call can be made.
(2) Speed dialing or one-touch
dialing will not work.
(3) Speaker silent during on-hook
dialing.
(4) Dial does not switch between
tone and pulse.
(5) Telephone does not ring.
Panel-main harness between the main PCB and the
l
control panel PCB
Control panel PCB
l
Low-voltage power supply PCB
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Main PCB
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LCD
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Panel-main harness between the main PCB and the
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control panel PCB
Control panel PCB
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FPC key
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Main PCB
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FPC key
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Control panel PCB
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NCU PCB
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Main PCB
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Ordinary dialing function (other than the speed and
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one-touch dialing)
If it works normally, check the main PCB; if not, refer
to item (1) above.
Ordinary dialing function (other than the on-hook
l
dialing with the hook key)
If it works normally, proceed to the following checks; if
not, refer to item (1) above.
Main PCB
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Speaker
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NCU PCB
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Main PCB
l
VI - 18
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